Inductive angle-of-rotation sensors are used, for example, in rotary encoders to determine the angular position of two machine parts rotatable relative to each other. In inductive angle-of-rotation sensors, excitation coils and receiving coils, for instance, in the form of conductor paths, are applied to a shared printed circuit board that is fixedly joined to a stator of a rotary encoder, for example. Disposed oppositely to this printed circuit board is a further board often in the form of a graduated disk, on which electrically conductive and non-conductive surfaces are applied so as to alternate at periodic intervals as graduation region or graduation structure, and which is joined in torsionally fixed fashion to the rotor of the rotary encoder. When an electrical excitation field alternating over time is applied to the excitation coils, signals are generated in the receiving coils as a function of the relative angular position between rotor and stator.
Rotary encoders having inductive angle-of-rotation sensors are often used as measuring devices for electrical drives, to determine the absolute angular position of corresponding drive shafts.
German Published Patent Application No. 197 51 853 describes an arrangement for an inductive angle-of-rotation sensor in which two graduation tracks of a graduated disk, that is, of a graduation element are scanned by receiving coils on a printed circuit board. To prevent faulty signals from being generated, such angle-of-rotation sensors must be prepared with comparatively small manufacturing tolerances, especially if the receiving coils have a comparatively large outside diameter.
To be understood by manufacturing tolerances hereinafter are, in particular, fitting tolerances as well, which come about when mounting the angle-of-rotation sensor on a shaft to be measured. For example, such fitting tolerances or fitting inaccuracies may cause wobble motions of the rotor or inclined positions of the rotor and/or of the stator.